1. Field of the Invention
The present invention generally relates to handheld medical devices. More particularly, certain features, aspects and advantages of the present invention relate to such devices having control button assemblies on multiple sides, having an offset drive system, having a cannulated drive shaft and/or having a locking collet mechanism.
2. Description of the Related Art
Handheld medical devices are generally known in which a motor drives a surgical device having any of a number of different functions and operating characteristics. The surgical devices are interchangeable such that the same handpiece can be used with any of a number of surgical devices or cutter configurations.
In addition, U.S. Pat. No. 5,871,493 shows a handpiece in which fluid can be aspirated through the surgical device through an aspiration channel. The aspiration channel extends alongside a motor, which motor is axially aligned with the surgical device. Thus, the aspiration channel must be offset from the surgical device.
U.S. Pat. No. 6,221,088 shows a power handpiece for driving a surgical blade to cut anatomical tissue. A distal end of the handpiece couples to the surgical blade. A motor assembly can be installed in the handpiece to drive the surgical blade and a suction channel is provided in the handpiece body, with a portion of the handpiece body extending through a drive shaft that connects to the surgical blade. The surgical blade carries a sealing assembly to facilitate irrigation and suction. The motor is removed from the handpiece body for sterilization.